Hydraulic control mechanism



June 289-1932. f N. w. DORMANA 1,864,530

HYDRAULIC CONTROL MECHANISM l Filed June 1. 1931 Patented June 28, 1932 warren STATES PATENT OFFICE NEAL W. DORMAN, OF TOLEDO, OHIO, ASSIGNOR TO THE TOLEDO & TOOL COM- i PANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO HYDRAULIC CONTROL MECHANISM -Application :Bled June 1, 1931. Serial No. 541,173.

This invention relates to hydraulic control mechanism which is adapted to be operated intermittently from a continuously operating pump and without the interpositlon. of a pressure accumulator. It is of special utility in controlling the operation of the clutch on a large power press or in controlling other machines which are of such size and power that manualy control is an arduous task.

One of the objects of the invention is to provide a vhydraulic control device in whlch turned to the tank 10 through the pipe 13. Pipes 12 and 13 are also connected by a by-pass 14 in which is a relief valve'15 which opens at a predetermined pressure to prevent overloading the system.

The housing 7 is formed with a cylinder 16 in which a piston 17 is mounted for recprocation. The cylinder 16 is provided with an extension 18 through which the stem 19. of the piston extends and which contains a spring 20 for acting on the piston 17 in oppothere is substantially no pressure in the line,l sition to the fluid pressure through the cyland no power consumed except when the machine is being operated, although the pump normally Voperates continuously.

Another important object is to promote safety by providing a control device whereby the machlne isautomatically brought to a stop by mechanical means, even if there is no pressure accumulatOI?` ,connected with the control device and t-he pump may have ceased to operate.

The specific construction off; the invention in its` preferred form and the advantages resulting therefrom will be more particularly described in the accompanying drawing, in which- Figure 1 is a. diagrammatic View illustrating the control system;

Figure 2 is an enlarged central longitudinal section through the cylinder` and valve' mechanism; l

Figure 3 isa section taken substantially on the line 3-3of Fig. 2

Figure 4 is a section taken on the line 4--4 of'Fig. 3; and

Fi ure 5 is a section taken on the line 55 of Fig. 3, but with the valve in an intermediate position.

The hydraulic control mechanism to which the invention relatesincludes a housing 7 formed with a bracket 8 by which it may be attached to the machine Vto be controlled. The Huid pressure is developed by a pump 9'which may be of any suitable type and is adapted to becontinuously driven. The fluid,

which is preferably oil, is drawn from a Stora e tank 10\through a pipe 11 and 1s force. 'under pressure throu h the pipe 12 to thegcontroljfmechanism. he fluid 1s rerelieved. The piston is provided with a cup 21 or other suitable means to prevent leakage of the fluid. The outer end of the piston rod 19 may be connected to a b ell crank 22 or to any other mechanical element for transmitting power to the clutch or'other mechanism tobe controlled.

The cylinder 16 is formed on one side with a valve housing 23-into which a port 24 leads from the inner end of the cylinder. A seat 25 is secured in the bottom of the housing 23 and has a port 26 in registry with the port 24. A valve 27 is disposed Within the housing 23 between the seat 25 and a cap 28 which is secured to the housing. The valve is secured on a spindle 29 which is mounted for rocking movement in the seat 25 and -cap 28 and which is provided with a crank arm 30 adapted to be connected witha suitable tripping device or shifting the valve to render the control mechanism effective or to release the same. The cap 28 is formed internally with anannular chamber 31 having aport 32 connected with .the pressure line 12. The vseat 25 is formed with a cavity 33 cmnected through a port 34 to thc return or exhaust pipe 13. A dowel pin 35 is mounted in the housing 7 'and extends through the seat 25 into an arcuate recess 36 in the valve 27 concentric with the axis 29. This pin limits the rocking movement of the valve in either direction. The valve 27 has two diametrically opposed ports 37 and 38 therethrough'and also has an arcuate recess 39.

The valve 27 is shown in Fig. 5 in an intermediate position. When the .valve is rocked to bring the port 37 in registry with`the ort 26, pressure will be admitted from the ine 12 through the chamber 31, ports 37 and 26 to the cylinder so that the piston will be moved in opposition to the spring 20 to actuwill then be in position to connect the port ate the mechanism which engages the clutch or eifects any other function for which the hydraulic control is used. When the valve is rocked to bring the port 38 into communication with the cavity 33, the arcuate recess and port 34 into the return line 13. Also,

the uid which is being pumped into the line 12 will pass freely through chamber 31, port 38, cavity 33 and port 34 directly into the return line 13 so that'no 'pressure will be developed and-practically no power will be consumed bythe operation of the pump.

When the valve is in normal position as above described, with the ports 32 and 26 both communicating with the return' or exhaust line 13, the piston 17 will be held by the spring 20 in the position shown in Figs. 1 and 2, and it is to be understood that the clutch or otherV member controlled by the piston is in inactive position. When the valve is rocked, either automatically or manually through the mediumof the crank arm V30, to its other extreme. position, fluid pressure 'will act on the piston'17 to overcome the pressure 'of the spring 2O and to shift the con trolled member to active position. In case the pump becomes inoperative, however, or for any other reason the pressure fails, the controlled member will always be returned to inactive position as soon as the valve is Y returned to .its normal position. This feature is of the utmost importance as a safety device.

Whilethe invention is primarily intended for use in controlling the clutch of a power.

press, it is also adapted for other uses and and the exhaust port and one of the holes besaid channel being idleand the other holebeing in communication with the delivery port in another position of the valve.

- 2. In combination, a valve housing, a seat within said housing having a pressure delivery portand an exhaust port, a rotatable valve on said seat having two holes therethrough, a pressure supply chamber, said valve being movable to one-'position in which one of said holes is closed by the seat and the otheroffsaid holes ai'ords communication between said pressure supply chamber and said delivery port, said valve being movable to another position -in which the irst of said holes affords direct communication between said supply chamber and said exhaust port while the second hole is closed by the seat, said valve having a channel which, in the'last described position of the valve aiit'ords communication between said delivery port and the exhaust port.

3. In combination, a valve housing, a seat within vsaid housing having a pressure delivery port and an exhaust port, a rotatable valve on said seat having two holes therethrough in such position that the valve may be selectively moved to bring one hole in registry with the pressure delivery portwhile the other hole is closed by the seat, or to bring said other hole in registry withthe exhaust port while the rst is closed by the'seat, a pressure supply chamber on the side of the valve opposite to said seat and in constant communication with both of said holes, said valve having a channel affording communication between said pressure delivery port and said exhaust port while the valve is in position to connect the pressure supply chamber with the exhaust port.

In testimony whereof I have hereunto signed my name to this specification.

NEAL W. DORMAN.

its construction may be considerably modified without departing from the essential scope of the invention as defined in the appended claims.

What I claim is 1. In combination, a valve housing, a seat within the housing, a rotatable valve on said seat, said-housing including a cap holding the valve on its seat and .formed with an annular chamber therein provided with a pressure supply port, said seat having a pressure del livery port therethrough and also an exhaust f` port, said valve having two holes therethrough and a channel in the base adjacent the seat, said channel establishing unrestricted communication between the delivery port lao 

